Rosuvastatin and atorvastatin have finished neck and neck in a major trial comparing the blockbuster statins’ efficacy at tackling coronary atherosclerosis.
The
study, funded by the developers of rosuvastatin (Crestor), comes as the patent for atorvastatin (Lipitor) expires this month in the US, reportedly to be followed in Australia in May next year.
The trial of more than 1000 patients with coronary disease found that high doses of either rosuvastatin or atorvastatin resulted in significant regression of coronary atherosclerosis — the primary endpoint — after two years of treatment.
Patients who received rosuvastatin achieved lower LDL and higher HDL cholesterol levels than those in the atorvastatin group, but overall the degree of regression of atheroma volume was similar in both groups.
"Either regimen can be used to reduce the atheroma burden for the purpose of secondary prevention," the study authors wrote in the New England Journal of Medicine.
Dr Jason Kaplan, a Sydney cardiologist, said the study confirmed the two statins were equally effective.
The imminent arrival onto the market of generic versions of the world's most-prescribed drug was going to be "good economically for everyone", he said.
"I don’t think there's a need to transfer everyone over to Crestor," Dr Kaplan said.
"Even in the other trials, the absolute differences between [atorvastatin and rosuvastatin] are still fairly small."
However there were often subtle chemical differences in new generics compared with the original compounds, so some patients could experience small changes in tolerability when switching to generics, Dr Kaplan added.
Associate Professor Leon Simons, a lipid specialist at the University of NSW, said while the two drugs had "very similar and favourable effects" on coronary lesions, the study showed about one-third of patients overall still had disease progression.
It did not compare how the drugs impacted on clinical outcomes or survival, he added.
Patients in the trial, known as SATURN, received daily treatment with either 40mg rosuvastatin or 80mg of atorvastatin. Preliminary
results were released in September.
Meanwhile debate continues over how long rosuvastatin will remain protected by patent in Australia, with the first generic versions of the drug appearing on the Australian Register of Therapeutic Goods last week.
Its US patent currently extends to 2016, but Associate Professor Philip Clarke, a health economist at the University of Sydney, said its status in Australia was currently unclear. Some industry specialists had argued it was not protected, he said.
Rosuvastatin manufacturer AstraZeneca declined to comment on its patent status.
In May, the company lost a federal court case in which it challenged the Health Minister’s decision to list Crestor and Lipitor in the same PBS therapeutic group.
PBS prices are affected by the lowest-priced drug within each group — hence when Lipitor comes off patent, the price of Crestor will be driven down as a result.